Intermittent mechanism for motion-picture projecting mechanisms



'March 31, 1953 J. W. LANG, JR INTERMITTENT MECHANISM FOR MOTION-PICTURE PROJECTING MECHANISMS Filed Sept. 9, 1950 IN VEN TOR.

daA/z A73 fate/ e9- Patented Mar. 31, 1953 INTERMITTENT MECHANISM FOR MOTION- PICTURE PBOJECTING MECHANISMS JOB-51W; Lang, In, Chicago, Ill.,"assignor"to De'Vry Corporation, 0

of Illinois hicago, 111., a corporation Applicationseptember 9, 1950, Serial,No.184,0 04

This inventionrelates to certain new and useful improvements in intermittent mechanism for motion picture projecting mechanisms. More particularly the invention concerns the provision of a film actuating claw having a plurality of equally spaced apart teeth for engaging the aper-' tures of a film for intermittently moving the film relative to an apertured plate over which the film strip is payed in a manner well known in the art.

An object of this invention is to provide the i tooth of the claw which is commonly called the action tooth, with a shoe formed of wear resisting material, thereby to extend the life of the claw. This action tooth is the only tooth of the claw which engages the film during normal perfect sprocket operation, the other teeth of the claw on opposite sides of the action tooth being auxiliary teeth and normally engaging the film only in the event of a tear or rupture of the film at the aperture engaged by the action tooth. Consequently, by reason of the heavy duty imposed upon this action tooth in the intermittent moving of the film, unless protected it soon becomes worn and rendered ineffective for its intended purpose. As before stated, an object of this invention is to protect this action tooth against wear.

Other objects will appear hereinafter.

The invention consists in the novel combination and arrangement of parts to be hereinafter describedand claimed.

The invention will be best understood by reference to the accompanying drawings showing the preferred form of construction, and in which:

Fig. 1 is a fragmentary perspective view of an intermittent mechanism showing my improved claw associated therewith;

Fig. 2 is a fragmentary side elevational view of the same showing the film in longitudinal section;

Fig. 3 is an edge view taken substantially on line 3--3 of Fig. 2;

Fig. 4 is an enlarged side elevational view of the claw embodying my invention;

Fig. 5 is an edge view of the same taken substantially on line 5-5 of Fig. 4; and

Fig. 6 is a fragmentary view similar to Fig. 4 showing a modified form of construction.

The objects of this invention are best accomplished by the preferred form of construction as shown in theaccompanying drawings, in which drawings I have illustrated a slide l0 providing an integral claw ll consisting of an action tooth l2 equally spaced apart from adjacent parallelly extending auxiliary steel teeth I3. This action 1 Claim. (01. 88--1 8.4)

tooth is. so -called because in the normaloperation of a moving picture projecting apparatus this tooth is the only tooth of the claw which engages the film, thef'other two steelteeth l3 'hing auxiliary 'teeth'du'e to the fact thattheir engagement with the film takes place upon enlargement of the aperture or tear of the film in the area of the aperture which is engaged by the action tooth l2.

Such being the case, it is manifest that the action tooth in its operation of moving into and out of the aperture to engage the film will in a relatively short time be worn to a condition such that it will fail to perform the function required of it. To eliminate this undue wear upon the action tooth, I provide a shoe M of elongated fiat formation and of a thickness substantially equal to one-half of the thickness usually required of an action tooth.

The claw provides a forwardly extending steel ledge I5 which is of a thickness equal to the thickness of the shoe I4 and which ledge l5 and shoe 14 together provide the action tooth. Inwardly of this ledge 15 and extending into the body of the claw H is a slot l6 into which the inner end portion of the shoe l4 frictionally fits. It is preferable that the shoe [4 be welded or oemented by a suitable cement within the slot [6 and to the ledge l5. This shoe may be formed of relatively hard material, such for example a sapphire. This shoe l4, when projected into the film aperture, presses down on the film to pull the same down. The abrasive effect of the film edge upon the shoe is resisted by virtue of the hardness of the shoe. Reciprocation of the slide H1 is accomplished in a manner substantially similar to that disclosed in United States Letters Patent No. 2,420,444, granted May 13, 1947, on an intermittent mechanism. In accomplishing this reciprocation there is employed a cam I! mounted on a shaft [8 and operating in a slot I9 formed in the slide Ill.

Oscillation of the slide relative to its mounting 20 is likewise accomplished in substantially the same manner as that disclosed in the aforesaid patent and in which there is employed a cam 2| operating in a slot 22 formed in the slide II].

In the form shown in Fig. 6 I provide as the intermediate tooth a sapphire insert l4 mounted in a slot l5 and secured therein by cement or the like.

By the foregoing construction I have provided a claw with an action tooth capable of withstanding the undue wear normally imposed upon such tooth. This I accomplish by a structure Having thus described myinvention, whatrI'.

claim as new and desire to protect by Letters Patent is:

A device of the class described'comp'rising a slide, an intermittent film mechanism, a claw integral with the slide at one end thereof and comprising an action tooth and auxiliary teeth on opposite sides of the action tooth in parallel relation with respect thereto, said action tooth comprisingafledg'e having-relativelyflat sides'and providing a slot extendingbeneath' andina substantially' horizontal plane with 'respectto'o'ne ofsaid. sides, a, shoe formed of wear resisting material and of elongated formation having one end thereof adhesively fixed in said slot with a side thereof in intimate and parallel relation with a side of said ledge and having its free end portion extending beyond the edge of said ledge and terminating in the same vertical plane with respect to theauxiliary; teeth.

JOHN W. LANG, JR.

REFERENCES CITED The following references are of record in the filef his p nt UNI QED STATES PATENTS Number Name Date 1,327,226. Le-Long Jan. 6, 1920 2,233,839 Heurtier Mar. 4, 1941 2552,45? Raskin May 8, 1951 FOR GN PATE TS Number- Country; Date 370,956 Great Britain Apr. .8, 1932 501,188 Great Britain -Feb. 22, .1939 

